Safety and Long-term Efficacy of Stent-assisted Coiling for the Treatment of Complex Posterior Cerebral Artery Aneurysms

Endovascular Treatment in Precommunicating Segment Aneurysms of Posterior Cerebral Artery

BACKGROUND

Precommunicating (P1) segment aneurysms of the posterior cerebral artery are rare, with few studies reported to date. Herein, we address the clinical and radiologic outcomes of their endovascular treatment.

METHODS

For this study, we retrieved prospectively collected data on 35 consecutive patients with 37 P1 aneurysms, analyzing the clinical ramifications and morphologic outcomes of treatment. All subjects received endovascular interventions between January 2001 and October 2021.

RESULTS

There were 16 aneurysms (43.2%) of P1 segment sidewalls and 21 (56.8%) at P1/posterior communicating artery junctions. Five (13.5%) were fusiform, and 14 (37.8%) were ruptured. In 14 patients (40%), 16 aneurysms (43%) were associated with intracranial arterial occlusive disease of the anterior circulation. Selective coiling was undertaken in 34 aneurysms (91.9%), using single (n = 24) or double (n = 4) microcatheters, microcatheter protection (n = 2), or stents (n = 4); and trapping was done in 3 (8.1%). No procedure-related morbidity or mortality resulted. Excluding the trapped lesions, angiographic follow-up of 29 aneurysms obtained >6 months after embolization (mean, 12.4 month) revealed stable occlusion in 21 (72.4%), with some recanalization in the other 8 (minor: 3/29, 10.4%; major: 5/29, 17.2%).

CONCLUSIONS

Aneurysms of P1 segment (vs. other locations) are strongly associated with intracranial arterial occlusive disease of the anterior circulation and thus are likely flow related. Endovascular treatment of such lesions seems safe and efficacious, despite the array of technical strategies that their distinctive anatomic configurations impose.

A Recurrent Large Posterior Cerebral Artery Aneurysm Successfully Treated with Parent Artery Occlusion Using Somatosensory-Evoked Potential: A Case Report

Objective

Treatment of large posterior cerebral artery (PCA) aneurysm involving the P1-P2 segment is difficult by both neurosurgery and endovascular treatment. Balloon occlusion test (BOT) to identify precise peripheral collateral flow is difficult prior to parent artery occlusion (PAO). Besides, PAO at the aneurysm at this location can cause peripheral cortical infarction of the occipital and temporal lobes and/or perforator infarction involving the midbrain and thalamus perfused by the perforating artery arising from the P1-P2 segment. However, detection of the perforator during PAO is difficult.

Case Presentation

The patient was a 49-year-old woman. At the age of 43 years, a right large PCA aneurysm was discovered in the right P1-P2 segment. A simple technique coiling was performed. As recurrence was identified 1 year later, embolization was performed using a same procedure. Since further recurrences were later found, a third round of treatment was planned. Somatosensory-evoked potential (SEP) was recorded as intraoperative electrophysiological monitoring. Tortuosity of the right PCA was observed at the aneurysm neck and the distal right PCA could not be secured. We could neither perform stent-assisted coil embolization nor BOT in the right PCA. Hence, we inflated the balloon in the basilar artery and checked the collateral circulation routes retrograde into the right PCA from the right middle cerebral artery via a leptomeningeal anastomosis. PAO was performed on the right P1-P2 segment at the aneurysm neck. The signal of the SEP was not decreased, and the aneurysm was not visualized. Another coil was added to strengthen the PAO to the right P1 segment, which decreased the SEP amplitude in the extremities by 3 minutes after. As the last coil was thought to be occluding the perforator branching from the right P1 segment, it was removed without detaching. The SEP amplitude began to improve and recovered by 9 minutes after. There was no postoperative deficit. No recurrence of aneurysm was observed on MRA 9 months postoperatively.

Conclusion

During PAO at the P1 segment of large PCA aneurysm involving the P1-P2 segment, SEP may be helpful to prevent perforator infarction, even if perforating artery originating from the proximal portion of the aneurysm was not detected by angiography.

Braided stents assisted coiling for endovascular management of posterior cerebral artery aneurysms: a preliminary mid-term experience

PURPOSE

Posterior cerebral artery (PCA) aneurysms are rare. This study is to evaluate the preliminary experience of braided stents applied in PCA aneurysms treatment.

METHODS

Angiographic and clinical data of 28 PCA patients treated with braided stents from July 2016 and September 2020 were retrospectively analyzed.

RESULTS

A total of 28 PCA aneurysms were enrolled. 22 (78.6%) aneurysms were dissecting aneurysms, while 6 (21.4%) aneurysms were saccular aneurysms. Thirty-five braided stents were implanted with dual stents implanted in 7 cases. Immediate angiographic results show that Raymond class I was obtained in 13 patients (46.4%), Raymond class II was obtained in 4 patients (14.3%), and Raymond class III was obtained in 11 patients (39.3%). Perioperative hemorrhagic events occurred in 1 patient (3.6%). Twenty-four patients (85.7%) received angiographic follow-up, and the mean follow-up time was 11.2 ± 4.9 months. Two patients (8.3%) were confirmed with IA neck recurrence, and 3 patients (12.5%) were confirmed asymptomatic parent artery occlusion (PAO). The other 19 patients were confirmed promoted occlusion with 18 Raymond class I (75%) and 1 Raymond class II (4.2%). Twenty-seven patients (96.4%) received clinical follow-up, and the mean follow-up time was 32.2 ± 13.5 months. One patient (3.7%) confirmed the death event 2 weeks after discharge. The other 27 patients (96.3%) got favorable clinical outcomes with an mRS score of 0-2.

CONCLUSIONS

Braided stent-assisted coiling with a high occlusion rate and relatively low complication rate provides an alternative strategy in treating PCA aneurysms. Long-term outcomes need further randomized study with larger case numbers.

Diagnostic Impact of Monitoring Visual Evoked Potentials to Prevent Visual Complications During Endovascular Treatment for Intracranial Aneurysm

Introduction

The present study aimed to determine the incidence of intraprocedural visual-evoked potential (VEP) changes and to identify correlations with intraprocedural ischemic complications during endovascular treatment in patients with intracranial aneurysm related to visual function.

Methods

This study analyzed data from 104 consecutive patients who underwent endovascular coil embolization to treat intracranial aneurysms related to visual function under VEP and transcranial motor evoked potential (MEP) monitoring. We analyzed associations between significant changes in MEP and VEP, defined as a >50% decrease in amplitude, and both intraprocedural complications and postoperative neurological deficits. Factors associated with postoperative neurological deficits were also assessed.

Results

Treated aneurysms were predominantly located in the internal carotid artery (95%). Five (5%) were located in the posterior cerebral artery (PCA). Significant decreases in intraprocedural VEP occurred in four patients (4%), although one of those four patients did not show concomitant MEP decreases during procedures. Immediate salvage procedures avoided postoperative visual disturbances. All VEP decreases were transient and not associated with postoperative visual impairment. One of three cases who underwent intraoperative balloon occlusion test showed tolerance to balloon occlusion of the proximal PCA under VEP assessment; parent artery occlusion was performed without postoperative visual disturbance in that case.

Conclusion

Although significant VEP decreases occurred 4% during neuro-endovascular aneurysm treatment related to visual function, intraprocedural VEP monitoring identifies ischemic changes associated with visual pathways and facilitates prompt initiation of salvage procedures.

Superficial Temporal Artery (STA)-Posterior Cerebral Artery (PCA) Bypass through Zygomatic Anterior Temporal Approach for Complex PCA Aneurysm: Technique Notes

BACKGROUND

Posterior cerebral artery (PCA) aneurysms are rare and the majority are giant, dissecting, or fusiform in morphology. Proximal occlusion of PCA without revascularization causes a high risk of ischemic complications. This study aimed to evaluate the safety and validity of using superficial temporal artery (STA)-posterior cerebral artery (PCA) Bypass through zygomatic anterior temporal approach in complex PCA aneurysms.

METHODS

Trapping or resecting of the aneurysms and reconstruction of the distal PCA through a zygomatic anterior temporal approach were performed in 6 patients from June 2017 to August 2020. Postoperative angiography was used to confirm the obliteration of the aneurysms and the patency of bypass artery. Neurologic function was assessed by the modified Rankin Scale.

RESULTS

Four male and 2 female patients with a mean age of 43.8 years (Range, 21-58 years) were assessed. Subarachnoid hemorrhage occurred in 5 patients, including 3 patients with Hunt-Hess grade IV, 2 patients with grade III, and 1 patient with grade I. All PCA aneurysms were treated with trapping or resecting of the aneurysms and revascularization of the distal PCA. Postoperatively, all aneurysms were eliminated and no new permanent neurological deficit was found. During the follow-up, Modified mRS of all patients were improved: There were 2 patients with mRS Score 0, 1 patient with mRS Score 1, 1 patient with mRS Score 3, and 2 patients with mRS Score 4. The long-term graft patency rate was 100%.

CONCLUSION

The STA-PCA bypass appears to be a safe and effective method for the treatment of complex PCA aneurysms requiring supplementing the blood flow in the area of the PCA. We established a surgical route, allowing the procedure to be done through the zygomatic anterior temporal approach. This approach provides adequate operative field exposure and reduces retraction of the temporal lobe.

Stent-Assisted Coil Embolization for Acute Ruptured Dissecting Aneurysm at the P2 Segment of the Posterior Cerebral Artery: A Case Report

Objective

We report a case of ruptured posterior cerebral artery (PCA) dissecting aneurysm treated with stent-assisted coil embolization in the acute phase of ruptured aneurysm.

Case Presentation

A 60-year-old woman presented with sudden onset of severe headache followed by unconsciousness. CT showed severe subarachnoid hemorrhage. Digital subtraction angiography showed a dissecting aneurysm at the P2 segment of the right PCA. Stent-assisted coil embolization was performed for the ruptured dissecting aneurysm. Since thrombus was observed in the stent, ozagrel was administered intravenously, and the thrombus gradually disappeared during the follow-up period. She was discharged without neurological deficit.

Conclusion

Parent artery occlusion is widely performed for acute ruptured PCA dissecting aneurysm, but reconstruction with stent-assisted coiling is considered to be an effective therapeutic strategy.

Selection of approach and bypass for fetal-type posterior cerebral artery aneurysm: illustrative cases

BACKGROUND

Unlike in aneurysms of the adult-type posterior cerebral artery (PCA), in aneurysms of the fetal-type PCA, parent artery occlusion (PAO) results in vascular insufficiency and major ischemic strokes. Preservation or reconstruction of fetal-type PCAs is necessary to prevent these complications. Furthermore, it is necessary to select an appropriate bypass method and approach for revascularization of the PCA.

OBSERVATIONS

The authors report 2 cases of aneurysms of fetal-type PCAs that were successfully treated with PAO with revascularization. A 38-year-old man with a large unruptured right PCA aneurysm at the postcommunicating (P2) segment underwent trapping with superficial temporal artery–PCA bypass via the anterior temporal and subtemporal approaches. In addition, a 45-year-old woman with a left PCA aneurysm at the quadrigeminal (P3)–cortical (P4) segments resulting in subarachnoid hemorrhage underwent proximal clipping of the P3 segment via the occipital interhemispheric approach with an occipital artery–PCA bypass. Although she had perforator infarction, major ischemic stroke was prevented, and aneurysm occlusion was accomplished in both cases.

LESSONS

Aneurysms of fetal-type PCAs pose a risk of ischemia due to PAO. The combined use of bypass and revascularization should be considered to prevent major ischemic stroke after occlusion of the fetal-type PCA. However, perforator infarction is a concern.

Endovascular treatment of vertebral and basilar artery aneurysms with low-profile visualized intraluminal support device

Background

The Low-profile Visualized Intraluminal Support (LVIS) device is a self-expanding, nitinol, single-braid, closed-cell device that was recently developed for endovascular embolization of intracranial aneurysms. However, current knowledge regarding the use of LVIS devices to treat vertebral and basilar artery aneurysms is limited. We aimed to evaluate the feasibility, efficacy, and safety of the LVIS device for treating vertebral and basilar artery aneurysms.

Methods

Between January 2015 and December 2017, patients with vertebral and basilar artery aneurysms treated using LVIS stents were enrolled in this study. We analyzed patients’ demographic, clinical and aneurysmal characteristics, procedural details, complications, and angiographic and clinical follow-up results.

Results

We identified 63 patients with 64 vertebral and basilar artery aneurysms who underwent treatment with (n = 59) or without (n = 5) LVIS stenting, including 10 patients with ruptured aneurysms. Forty-one aneurysms were located at the vertebral artery, and 23 at the basilar artery. Intraprocedural-related complications developed in three (4.8%) patients, while none of these patients developed morbidities or died during follow-up. Three patients developed post-procedural complications (4.8%). Two patients experienced ischemic events immediately post-procedure. A minor permanent morbidity developed in one of the two patients (1.6%). The mortality rate was 1.6%, for that the patient died of brainstem hemorrhage after 1 month of follow-up. At a mean follow-up of 12.5 months, 39/43 (90.7%) patients had stable or improved aneurysms, and four (9.3%) had recanalized.

Conclusions

LVIS device of vertebral and basilar artery aneurysms may be an acceptable safety profile and may represent a reasonable treatment option in the short-term. Long-term and larger cohort studies are necessary to validate our results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02180-1.